A high school dropout (Kevin Hart, right) struggling with learning disabilities prepares for his GED with the tough-love help of his instructor (Tiffany Haddish) in "Night School."

A high school dropout (Kevin Hart, right) struggling with learning disabilities prepares for his GED with the tough-love help of his instructor (Tiffany Haddish) in "Night School." (Universal Pictures)

Am I asking too much of “Night School”? It’s no big thing, this new movie starring Kevin Hart and Tiffany Haddish, and nobody’s expecting a formula-, game- or life-changer. You just don’t want to leave feeling shortchanged.

Right?

A few cheap laughs.

Is that so wrong?

Director Malcolm D. Lee’s commodity squeaks by, barely, with solid comic assistance from the delightful Romany Malco (serenely panicked, every second) and Mary Lynn Rajskub (“blessed,” she keeps saying, even though her character’s domestic life is pure hell). Along with Rob Riggle, Al Madrigal and Anne Winters, they’re welcome company as the Hart character’s fellow night school students, prepping for the GED exam under the tough-love guidance of the overworked Atlanta educator portrayed by Haddish. There’s an orange-suited adult student Skyping in, too, a prisoner (Fat Joe) who watches his back every second while working through challenging mathematical equations remotely.

Hart’s production company helped put together “Night School,” and it’s Hart’s show by design, beginning with the 2001-set prologue. High school-age Teddy (Hart) copes with undiagnosed learning disabilities and an array of dyslexia-related difficulties. School is tough enough without being ritually humiliated and called out as “stupid” by Teddy’s nemesis, Stewart.

Seventeen years later, Teddy makes a decent living as a barbecue grill sales whiz, though he’s desperately in debt trying to impress his upscale girlfriend, Lisa (Megalyn Echikunwoke). A few setbacks later, dissembling and dodging the truth left and right, Teddy’s employed by a fast-food franchise called Christian Chicken (a deft poke at Chick-fil-A). Nights, he’s a reluctant student in the night school GED prep course, at the school whose principal (Taran Killam, overindulged and under-amusing) is Teddy’s high school tormentor.

Six credited screenwriters worked on this script, at various stages, which translates to 2.5 good jokes per man. “Night School” works best when it ditches the plot contrivances altogether and lets Haddish and Hart go at it with the trash talk. (At one point, they simply trade animal snarls, when words won’t suffice.)

The rest of the time the movie relies on clumsy, poorly staged mayhem, with a glaring lack of finesse in its physical comedy. In order to help Teddy focus on his learning, Haddish’s Carrie puts him in an MMA ring and punches him in the face, over and over. The movie has no idea how to work that bit, while also treating Teddy’s learning disabilities seriously. Director Lee and Haddish found low-comic gold in their recent smash, “Girls Trip”; I doubt anyone involved with “Night School” believes they’ve come up with something half as lively this time.

Judging from its weirdly frequent overdubbed punchlines, the film appears to have been shot as an R-rated release, then toned down for a PG-13. (Even so, the visual gags tend toward vomit and pubic hair.) Hart remains an audience-pleaser, though I confess I found him a little wearing here; Haddish, a fresher presence, can do only so much with a role that’s more function than form. The actors aren’t the problem with “Night School”; the material is. It’ll nonetheless likely prove a hit because of who’s in it, headliners and supporting ringers alike.